Air conditioning apparatus for



J. H. nAvis Re. 19,759, I 151R CONDITIONING APPARATUS FOR PAssBNGER M 2Sheets-sheet 1 w 9 l 9 l w N Original Filed Oct. 19. 1929 INVENTORATTORNEY Nov. 19, 1935. J. H. DAVIS, Re. 19,759

AIR CONDITIONING APPARATUS FOR PASSENGER CARS Original Filed Oct. 19,1929 2 Sheets-Sheet 2 Reiscued m... 19, 1935 UNITED STATES PATENT OFFICEm CONDITIONING APPARATUS FOR PASSENGER CABS Jesse B. Davis, Baltimore,Md., assignor to B. F.

Sturtevant Compa y,

ration of Massachusetts 11, Mass 11 corpo- Original No. 1,843,210, datedFebruary 2, 1932,

Serial No. 400,929, October 19,1929. Application for reissue February 2,1992, Serial No.

3 Claims. (01. 011-) 2-: of Figure 1;

Figure 3 is a diagrammatic view of conditioning equipment designed tocarry out my invention;

Figure 4 is a top plan view of one end portion of Figure 1; Figure 5 isa top plan view of a portion of the half deck roof, showing the airdistributing ducts, Figure 6 is an enlarged detail sectional viewthrough the half deck of a car and the air conduit. Figure 7 is a viewsimilar to Figure 2, showing the use of a water spray filter instead ofa me-'- chanical filter.

Figure 8 is aview similar to Figure 4 showing 25 the organizationdisclosed in Figure 7.

Figure 9 is a view partly in elevation and partly in section of thewater spray filter shown ln Figures '1 and 8. v

In Figure 1 of the drawings, I have shown a so typical layout for airconditioning equipment for an individual car system; that is tosay,.this car is a unit completely equipped with the necessarygenerating and refrigerating facilities for air conditioning. 35 Toprovide the electrical energy required for the air conditioningequipment a nominal 10 kilowatt, 110 volt, direct current generator 6,is

mounted beneath the car floor and is driven by" a positive drive fromthe car axle. In addition, 40 the necesary regulator for maintaining aconstant voltage above a certain critical speed, the necessary automaticswitch, etc., are provided. In addition, the car may be equipped with arotary converter whereby alternating current from wayside points, suchas depots and yards, may be converted to direct current so that the airconditioning equipment may be operated while the car is standing still.

A motor driven compressor lb of proper ca- 50 pacity is mounted beneaththe car floor, and compressed ammonia'is delivered thereby to thecondenser tank I beneath the car floor. The hot ammonia is cooled bypassing over water coils in the condenser tank Q. The. liquefied ammoniais then pmed through an expansion valve 9 and at v hdelivered to theevaporator tank Ill beneath the car fiocr. Here it circulates throughtubes surrounded by water and during the expansionthrough these tubeschills the water in the evaporator tank. From the evaporator the ammoniapasses back to the low pressure side of the compressor. I

The water contained'in the tubes of the condenser 9 becomes heated dueto cooling the compressed ammonia, and it is circulated by means 10 ofthe pump l0 and delivered to the center point of the cooling'tower II inthe comer of the car. Here the water is sprayed from sprayer ll, airfrom within or outside of the car is drawn through the sprayed water,thus cooling thewater by evaporation back to about the wet bulbtemperature of the air. The water is then available for reuse in thetubes of the condenser. The tower II is provided with a suitably closedinlet ll for admitting air thereto from within the 20 car, with asuitably closed inlet II for admitting air thereto from the outside ofthe car, andwith an outlet I I? at the top for discharging the heatedair therefrom to the external atmosphere.

The chilled water in the evaporator III is taken by the pump l2 and isdelivered to the surface 7 cooler l3 located overhead in the airconditioning compartment A located in the half deck zone at one end ofthe car. This cooler l9 consists of suitable form of piping of propermaterial to which is attached fins I4 for increasing the radiatingsurface, the coils being so arranged that as the airpasses over thesame, the heat in the air will be given up to the surfaces of thecooler.

Normally the air in the car will be recirculated between the passengerspace and the conditioning compartment, but provision is made by meansof a duct ii for theadmission of .the desired amount of outside freshair intothe air conditioning compartment. This is controlled by a 40suitable damper It. The outside fresh air is passed through an airfilter, which may be of a mechanical design, as shown at II in Figures1, 2 and 4, or of the water spray type, as shown at I1 in Figures 7, 8and 9,, which spray type filter may be included in a suitable watersupply circuit. The mechanical type of air filter is preferably usedbecause it occupies less space, weighs less, and its cost is less thanthe spray type of air filter, but the spray type filter may be used whenit is desired to filter the air by a washing action and to humidity itto a desired degree before cooling it.

After the air is cooled by passing over the surface cooler it, it isthen drawn into the motor driven centrifugal fans It, and delivered tothe air ducts II on each side of the car at thehalf deck.Asshowninl'lgures2and6,th eseducts are covered with insulation so as toprevent the chilled air within the duct from becoming heated due to theoutside light and the sunas well as the hot outside air during thesummer It being preferable to maintain the present pleasing lines of theinterior of the car, I avail myself of the space 22 now in presentconstruction in the half deck between the plate 23 and the half deckroof 24. the only change in the plate 23 is that I provide it withperforationsv or suitable grille work 25. Over the half deck roof 2, Isecure a plate 28 extending substantially the length of the car, therebyforming an air duct I. The sheet or plate 20 is provided on the insidewith suitable insulation 20. In the half deck roof 24, I provide atsuitable intervals openings 20* which establish communication betweenthe duct is and the space 22, through which the treated air may passfrom the duct into the space 22-, and in order to prevent objectionabledrafts from entering the car, I provide a perforated baille 2i, suitablysecured in the space 22 under, but spaced from the openings I8. The airpasses from the space 22 into the car through the perforations 25 of thehalf deck plate 23. In order that the admission of the conditioned airinto the car may be under controlpl provide dampers 21 for the openingsII which may be operated in any suitable mannor from within the car, andmerely for purposes of illustrating some means for operating thesedampers. I have shown the damper provided with a rack 28 which isengaged by a pinion 29 mounted on the operating rod 30 having a handwheel II in the car, but. of course, it will beunderstood that I do notlimit myself to this construction of damper operating means, as thereare other means that may be employed for this purpose. If it is foundthat the conditioned air has a tendencyto discharge into that end of thecarnearthe coolerintoogreatavolume.tbis can be corrected by closing someof the dampers at that end, thus directing the air discharge furtherback into thecar. 5

Theairfromtheinteriorofthecarisconducted through the ventilators II tothe surface cooler IS in compartment A and obviously air from the watertower also passes to compartment A through. the duct or connection I1.10

While I have shown a preferable location for the air ducts I, it isobvious that other dispositions and locations for these ducts may bevadopted without departing from the spirit of my invention. 1 Y 5 WhileI have named ammonia" as the refrigerant, it is, of course, understoodthat any suitable refrigerant maybe used.

What I claim is:

l. Iii-combination, in a temperature regulat- 2 ing device for passengercars, an air duct on the roof of the half deck of the car, portsextending from said duct through said roof, a half deck plate spacedfrom said roof to form a chamber in communication with said ports, andother 25 ports leading from said chamber into the car.

2 In combination, in a temperature regu1ating device for passenger cars,an air duct on the half deck roof of the car, a perforated half deckplate spaced from the roof, a wall extendso ing from saidplate to thesaid roof forming a chamber, ports leading from the air duct into saidchamber, and a baille plate in said chamber below said ports.

3. In combination, in a temperature regulat- :5 ing device for passengercars, air ducts'on the half deck roof of the car, a perforated half deckplate spaced from the roof, a wall extending from said plate to the saidroof forming a chamber, ports leading from the air ducts into said cham-4 ber, and a baile plate in said chamber below said ports, and damperscontrolling said ports.

JESSE H. DAVIS.

